فهرست مطالب

Iranian Journal of Mathematical Sciences and Informatics
Volume:9 Issue: 1, may 2014

  • تاریخ انتشار: 1393/02/30
  • تعداد عناوین: 8
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  • Mohammad Jahanshahi, Asghar Ahmadkhanlu Pages 1-12
    In this paper has been studied the wave equation in some non-classic cases. In the rst case boundary conditions are non-local and non-periodic. At that case the associated spectral problem is a self-adjoint problem and consequently the eigenvalues are real. But the second case the associated spectral problem is non-self-adjoint and consequently the eigenvalues are complex numbers,in which two cases, the solutions of the problem are constructed by Fourier method. By compatibility conditions and asymptotic expansions of the Fourier coe cients, the convergence of series solutions are proved. At last series solution are established and the uniqueness of the solution is proved by a special way which has not been used in classic texts.
    Keywords: Wave equation, Non, local, amp, Non, periodic Boundary Conditions, Asymptotic Expansion
  • R. A. Borzooei, A. Rezazadeh, R. Ameri Pages 13-29
    In this paper, we introduce the notion of hyper pseudo B C K - algebras, which is a generalization of pseudo BCK -algebras and hyper BCK -algebras and we investigates some related properties. In follow, we de ne some kinds of hyper pseudo BCK -ideals of a hyper pseudo BCK - algebra and we find the relations among them. Finally, we characterize the hyper pseudo BCK -ideals of type 4 generated by a nonempty subset.
    Keywords: Hyper pseudo BCK, algebras, Hyper pseudo BCK, ideals, Gener, ated hyper pseudo BCK, ideals
  • Massoud Aman Pages 31-42
    In this article, we consider the matrix equation $AXB=C$, where A, B, C are given matrices and give new necessary and sufficient conditions for the existence of the diagonal solutions and monomial solutions to this equation. We also present a general form of such solutions. Moreover, we consider the least squares problem $min_X |C-AXB |_F$ where $X$ is a diagonal or monomial matrix. The explicit expressions of the optimal solution and the minimum norm solution are both provided.
    Keywords: Matrix equation, Diagonal matrix, Monomial matrix, Least squares problem
  • A. Gharibkhajeh, H. Doostie Pages 43-51
    In this paper we develop an analog of the notion of the con- jugacy graph of nite groups for the nite semigroups by considering the Green relations of a nite semigroup. More precisely, by de ning the new graphs $Gamma_{L}(S)$, $Gamma_{H}(S)$, $Gamma_{J}(S)$ and $Gamma_{D}(S)$ (we name them the Green graphs) related to the Green relations L; R; J; H and D of a nite semigroup S, we first attempt to prove that the graphs $Gamma_{D}(S)$ and $Gamma_{H}(S)$ have exactly one connected component, and this graphs for regu- lar semigroups are complete. And secondly, we give a necessary condition for a nite semigroup to be regular. This study shows an intrinsic di er- ence between the conjugacy graphs (of groups) and the Green graphs (of semigroups) as well. Finally, our calculations include two kinds of semi- groups, mostly involving the well known Lucas numbers, and examining the proved assertions.
    Keywords: Conjugacy graph, regular semigroup, Green relations
  • Amir Ehsani, Yuri Movsisyan Pages 53-62
    In this paper paramedial, co-medial and co-paramedial binary multiquasigroups are considered and a characterization of the corresponding component operations of these multiquasigroups is given.
    Keywords: Medial, paramedial, co, medial, co, paramedial, multiquasigroup, mode
  • Parastoo Habibi, Asadollah Razavi Pages 63-69
    In this paper we study generalized symmetric Berwald spaces. We show that if a Berwald space $(M,F)$ admits a parallel $s-$structure then it is locally symmetric. For a complete Berwald space which admits a parallel s-structure we show that if the flag curvature of $(M,F)$ is everywhere nonzero, then $F$ is Riemannian.
    Keywords: Homogeneous Finsler space, Symmetric space, generalized Symmetric space, Berwald space
  • Assadollah Niknam, Saeedeh Shamsi Gamchi, Mohammad Janfada Pages 71-80
    In this paper we introduce the cone bounded linear mapping and demonstrate a proof to show that the cone norm is continuous. Among other things, we prove the open mapping theorem and the closed graph theorem in TVS-cone normed spaces. We also show that under some restrictions on the cone, two cone norms are equivalent if and only if the topologies induced by them are the same. In the sequel, we introduce the notion of algebraically cone metric and we will show that every algebraically cone metric space has a topology.
    Keywords: Cone bounded, Equivalent cone norms, Algebraically cone metric
  • Kostaq Hila, Bijan Davvaz, Krisanthi Naka Pages 81-98
    In this paper, we introduce and study the concepts of prime left, semiprime left and irreducible left hyperideals in ternary semihyper- groups and investigate some basic properties of them. We introduce the concepts of hyper lter and hypersemilattice congruence of ternary semi- hypergroups. We give some characterizations of hyper lters in ternary semihypergroups. Some relationships between hyper lters, prime hyper- ideals and hypersemilattice congruences in ternary semihypergroups are considered. We also introduce the notion of hyperideals extensions in ternary semihypergroups and some properties of them are investigated.
    Keywords: Semihypergroup, Ternary semihypergroup, Hyperideal, Prime left hyperideal, Semiprime left hyperideal, Irreducible left hyperideal, Hyper lter, Left m, system, Left i, system, Left p, system